The present invention relates to a process for producing a rubber wet master batch, a carbon black-containing rubber wet master batch obtained by the above process and a rubber composition and a tire prepared by using the above master batch. More specifically, the present invention relates to a process for efficiently producing a rubber wet master batch in which use of a carbon black granulated substance granulated by a wet method and staying in a non-drying state for preparing a filler-dispersed slurry containing carbon black makes it possible to improve more a dispersibility of carbon black in the rubber, control more readily a content thereof and enhance a reinforcing property, an abrasion resistance, a low heat generating property and a cracking resistant growing property of the rubber than a case using a generally commercially available dried carbon black granulated substance and carbon black subjected to no granulation operation (so-called fluffy carbon, and hereinafter referred to as non-granulated carbon), a carbon black-containing rubber wet master batch obtained by the above process and a rubber composition and a tire prepared by using the master batch described above.